25 research outputs found

    CURVACE - CURVed Artificial Compound Eyes

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    International audienceCURVACE aims at designing, developing, and assessing CURVed Artificial Compound Eyes, a radically novel family of vision systems. This innovative approach will provide more efficient visual abilities for embedded applications that require motion analysis in low-power and small packages. Compared to conventional cameras, artificial compound eyes will offer a much larger field of view with negligible distortion and exceptionally high temporal resolution in smaller size and weight that will fit the requirements of a wide range of applications

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

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    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

    An electrophysiologic computational model of the zebrafish heart

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    In recent years there has been a growing interest in the zebrafish thanks to its physiological characteristics similar to humans '. The following work aims to create a full electrophysiological computational model of the zebrafish heart with the ultimate purpose of assessing the influence of pathologies and drug administration. The model considers a full body and the two-chambers of a 3 days post fertilization zebrafish. A four-variable phenomenological Action Potential model is used to describe the action potential of different regions of the heart. Tissue conductivity has been calibrated in order to reproduce the activation sequence described in literature. This model allows the evaluation of the main electrophysiological parameters in terms of activation sequence and timing, AP morphology (i.e., APD{90}, AP amplitude, maximum and minimum AP derivatives), and ECG morphology (i.e., P-wave, T-wave, and QRS-complex amplitudes and durations)

    Nd: YAG surgical laser effects in canine prostate tissue: temperature and damage distribution

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    An in vitro model was used to predict short-term, laser-induced, thermal damage in canine prostate tissue. Canine prostate tissue samples were equipped with thermocouple probes to measure tissue temperature at 3, 6, 9 and 12 mm depths. The tissue surface was irradiated with a Nd:YAG laser in contact or non-contact mode for up to 20 s, using powers from 5 to 20 W. Prediction of thermal damage using Arrhenius theory was discussed and compared to the in vitro damage threshold, determined by histological evaluation. The threshold temperature for acute thermal tissue damage was 69 +/- 6 degrees C (means +/- SD), irrespective of exposure time. Contact mode laser application caused vaporization of tissue, leaving a crater underneath the fiber tip. The mean extent of tissue damage underneath the vaporization crater floor was 0.9 +/- 0.6 mm after 5, 10 or 20 s of contact mode laser irradiation at 10 W, whereas 20 W non-contact exposure up to 20 s causes up to 4.7 +/- 0.2 mm coagulation necrosis. It was concluded that short-term acute thermal tissue damage can be comprehensively described by a single threshold temperature
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